diff --git a/package-lock.json b/package-lock.json
index 9996385..1d4826c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -447,10 +447,13 @@
       "dev": true
     },
     "async": {
-      "version": "3.0.1",
-      "resolved": "https://registry.npmjs.org/async/-/async-3.0.1.tgz",
-      "integrity": "sha512-ZswD8vwPtmBZzbn9xyi8XBQWXH3AvOQ43Za1KWYq7JeycrZuUYzx01KvHcVbXltjqH4y0MWrQ33008uLTqXuDw==",
-      "dev": true
+      "version": "2.6.1",
+      "resolved": "https://registry.npmjs.org/async/-/async-2.6.1.tgz",
+      "integrity": "sha512-fNEiL2+AZt6AlAw/29Cr0UDe4sRAHCpEHh54WMz+Bb7QfNcFw4h3loofyJpLeQs4Yx7yuqu/2dLgM5hKOs6HlQ==",
+      "dev": true,
+      "requires": {
+        "lodash": "^4.17.10"
+      }
     },
     "async-each": {
       "version": "1.0.1",
@@ -3358,15 +3361,6 @@
         "uglify-js": "^3.1.4"
       },
       "dependencies": {
-        "async": {
-          "version": "2.6.2",
-          "resolved": "https://registry.npmjs.org/async/-/async-2.6.2.tgz",
-          "integrity": "sha512-H1qVYh1MYhEEFLsP97cVKqCGo7KfCyTt6uEWqsTBr9SO84oK9Uwbyd/yCW+6rKJLHksBNUVWZDAjfS+Ccx0Bbg==",
-          "dev": true,
-          "requires": {
-            "lodash": "^4.17.11"
-          }
-        },
         "source-map": {
           "version": "0.6.1",
           "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
diff --git a/package.json b/package.json
index 8e0e87b..5a10166 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,7 @@
   "license": "Apache-2.0",
   "devDependencies": {
     "ajv": "6.10.0",
-    "async": "3.0.1",
+    "async": "2.6.1",
     "browserify": "16.2.3",
     "chai": "4.2.0",
     "chalk": "2.4.2",